Transcript Document

Journée thématique DAPNIA
«Almants supraconducteurs»
High Temperature Superconductivity (HTS)
Opportunities & Challenges;
R&D Activities in the US
Yukikazu IWASA
Francis Bitter Magnet Laboratory
Massachusetts Institute of Technology
Cambridge, MA 02139-4208
Orme des Merisiers, Bât. 774, Amphi Bloch, Saclay
lundi 3 juillet 2006
Y. IWASA (FBML)
[email protected]
DAPNIA Day  HTS
Saclay (03/07/2006)
1
Outline
• Review of LTS & HTS Characteristics
• HTS  Current Status (Bi-2223; Bi-2212; YBCO; MgB2)
• Key issues
• Opportunities
 HTS R&D Activities in the US
• Challenges
• Important Activities for HTS
• Market Penetration for HTS
• Conclusions
Y. IWASA (FBML)
[email protected]
DAPNIA Day  HTS
Saclay (03/07/2006)
2
oHc2 vs.Tc Plots for LTS & HTS
YBCO
OXIDE
150
(n=2)
Bi2Sr2Can-1CunO2n+4: OXIDES
(BSCCO)
(n=3)
oHc2 [T]
Bi-2212
100
50
Bi-2223
MgB2
COMPOUND
Nb3Sn
COMPOUND
Nb-Ti
ALLOY
0
0
Y. IWASA (FBML)
[email protected]
20
40
60
Tc [K]
80
DAPNIA Day  HTS
Saclay (03/07/2006)
100 110
3
105
Jc Data: LTS @4.2 K
HTS @4.2 K & Above
104
Jc [A/mm2]
Useful
range for
magnet
YBCO (4.2; 75)
Bi-2212 (4.2)
103
Bi-2223 (4.2; 20)
102
MgB2 (4.2;20)
10
00
55
[Based on graph by P. Lee (12/2002; UW)]
Y. IWASA (FBML)
[email protected]
Nb-Ti (1.8; 4.2)
10
10
B [T]
15
15
DAPNIA Day  HTS
Saclay (03/07/2006)
Nb3Al
( 4.2)
Nb3Sn (1.8; 4.2)
20
20
25
25
30
30
4
Bcenter vs Top Zones for LTS & HTS Magnets
50
YBCO
Bi-2223/2212
Bcenter [T]
40
MgB2
30
Nb3Sn
20
Nb-Ti
10
0
0
10
20
30
40
50
60
70
80
90
100
Top[K]
HTS Opportunities: higher fields over wider Top range
Y. IWASA (FBML)
[email protected]
DAPNIA Day  HTS
Saclay (03/07/2006)
5
HTS  Current Status
Bi-2223
 Available NOW as “magnet grade conductor”
 Only as TAPE
Sumitomo Electric Bi-2223
4.2 mm
0.22
[T. Kato (Sumitomo) (2006)]
• Difficult to reduce AC losses  suitable for DC coils
• “Pancake” coils rather than “layered” coils
 many joints
 “large” radial gaps needed in multi-coil inserts
Y. IWASA (FBML)
[email protected]
DAPNIA Day  HTS
Saclay (03/07/2006)
6
HTS  Current Status (continuation)
Bi-2212
 Available in WIRE form
NEXANS Bi-2212 Wire
• Easier to minimize AC losses
• “Layered” coils
 Suitable for multi-coil “inserts”
 Still under development
0.8 mm
18 sub-element each of
37 filaments
[Jean-Michel Rey (2006)]
Y. IWASA (FBML)
[email protected]
DAPNIA Day  HTS
Saclay (03/07/2006)
7
HTS Current Status (continuation)
YBCO
 Usable at LN2 temperatures (>64 K)
 Considered by many that YBCO less expensive than
Bi-2212/2223  low materials costs, e.g., no Ag
 Only as TAPE  same negative points as Bi-2223
 Even AFTER MORE THAN 10 years, still the longest
available ~100 m
Y. IWASA (FBML)
[email protected]
DAPNIA Day  HTS
Saclay (03/07/2006)
8
HTS  Current Status (continuation)
MgB2
 Available as WIRE  same positive points as Bi-2212
 Considered by many to be price-competitive against Nb-Ti
 Jc (>10 K) still much less than Nb-Ti’s (@4.2 K)
 More brittle than Nb-Ti
0.87 mm 36-filament wire
MgB2
Nb barrier
Cu
[Mike Tomsic (Hyper Tech) (2006)]
Y. IWASA (FBML)
[email protected]
DAPNIA Day  HTS
Saclay (03/07/2006)
9
Key Magnet Issues vs. Top
Difficulty or Cost
Protection
Conductor
Mechanical
Stability
Cryogenics
0
Range of Operation
for LTS Magnets
Y. IWASA (FBML)
[email protected]
~100
Top [K]
Range of Operation
for HTS Magnets
DAPNIA Day  HTS
Saclay (03/07/2006)
10
Opportunities
Stability
• HTS magnets VERY stable  immune from disturbances,
e.g., mechanical, that still afflict LTS magnets
• ALL HTS magnets should be “adiabatic’’
→ higher J
 Saving in production cost
• Unnecessary to epoxy-impregnate HTS windings?
 Saving in production cost
Y. IWASA (FBML)
[email protected]
DAPNIA Day  HTS
Saclay (03/07/2006)
11
Opportunities (continuation)
• ALL HTS magnets, except those combined with LTS magnets,
should be dry, cryocooled!  the presence of liquid cryogen
in the system tends to make cryogenics too “visible” to the user
• TWO reasons why LHe NOT needed:
1. HTS magnets CAN operate well above LHe temperatures
2. “Large” temperature margins for HTS magnets
 [dT/dt  0]LTS not mandatory for HTS magnets
• ONE serious disadvantage for dry magnets:
 Nearly ZERO thermal mass for the cold body
 ENTER: solid-cryogen-cryocooled “dry” HTS magnets
Y. IWASA (FBML)
[email protected]
DAPNIA Day  HTS
Saclay (03/07/2006)
12
Cp(T) Plots
2.0
2.0
Llv = 2.56 J/cm3
for LHe
SNe
Ag
SN2
Cu
Cu
Pb
Pb
Ag
SNe
3 3K]
K]
[J/cm
CpCp
[J/cm
1.5
1.5
Phase transition
(35.6 K): 8.3 J/cm2
SNe
SN2
Pb
SN2
1.0
1.0
Ag
0.5
0.5
Cu
0.0
0
00
Y. IWASA (FBML)
[email protected]
10
10
20
20
30
40
30
40
Temperature
T [K] [K]
DAPNIA Day  HTS
Saclay (03/07/2006)
50
50
60
60
13
Opportunities (coontinuation)
• When MgB2 can replace Nb-Ti, and Bi-2212/2223 and/or
YBCO can replace Nb3Sn, it should be possible to make
magnets  NMR/MRI; HEP; even FUSION  entirely of
cryocooled HTS operating >10 K, with ZERO possibility of
quenches
 “Dry” magnet tends to make cryogenics “invisible”
Y. IWASA (FBML)
[email protected]
DAPNIA Day  HTS
Saclay (03/07/2006)
14
Opportunities for
LTS & HTS
Magnets:
Present & Future
• DC or ~DC
LTS: present
HTS: future
• DC or ~DC
LTS: proven
HTS: better?
• AC or DC
Hope hinges
on HTS
Applications
Current Status
Medical MRI
Magnetic Separation
LTS (marketplace); HTS (R&D)
LTS (marketplace); HTS (R&D)
Crystal (Si) grower
LTS (marketplace); HTS (R&D)
RESEARCH NMR/MRI LTS (marketplace); HTS (R&D)
LTS (marketplace); HTS (R&D)
DC field
MAGNET
HEP
LTS (“Teva;” LHC); HTS (R&D)
Electric Power  Conversion & Storage
LTS (TORE SUPRA; ITER); HTS (R&D)
Fusion
Generator
LTS (R&D); HTS (R&D)
SME
LTS (R&D); HTS (R&D)
Flywheel
HTS bulk disk (R&D)
Electric Power  Distribution
Transmission
HTS (R&D)
Transformer
HTS (R&D)
Fault current limiter
HTS (R&D)
Electric Power  End Use
HTS (R&D)
Motor
MAGLEV
Y. IWASA (FBML)
[email protected]
LTS (R&D); HTS (R&D)
DAPNIA Day  HTS
Saclay (03/07/2006)
15
HTS R&D Activities in the US
• Nearly ALL US superconductivity R&D activities on HTS
• Major federal government HTS R&D activities targeted to
devices (electric utilities & military) and YBCO
Sponsor
DOE
Principal Areas
1) HTS electric power devices; 2) YBCO
Air Force YBCO (lightweight magnets; protection)
Navy
NSF [b]
NIH [c]
Budget
~$40M/Y
~$10M/Y
Synchronous motors (Bi-2223) for ship propulsion $80M [a]
Operates the NHMFL national facilities
~$25M/Y
Pays for many LTS NMR & MRI magnets [d]
[a] Total for two motors, 5MW (2003) & 36.5MW (2006)
[b] National Science Foundation
[c] National Institutes of Health
[d] Supports, among others, four HTS NMR/MRI magnet projects currently at MIT
Y. IWASA (FBML)
[email protected]
DAPNIA Day  HTS
Saclay (03/07/2006)
16
Opportunities (continuation)
Selected 1-GHz NMR Magnet Projects
Based entirely on LTS
•
•
1 GHz NRIM (Japan)
1 GHz Oxford Instruments
Based on LTS/HTS
•
•
•
1 GHz: MIT (Bi-2223)
1.2 GHz: Grenoble/Saclay (Bi-2212)
1.3 GHz: NHMFL (Bi-2212)
Y. IWASA (FBML)
[email protected]
DAPNIA Day  HTS
Saclay (03/07/2006)
17
3-Phase MIT 1-GHz LTS/HTS NMR Magnet Project*
Phase 2 (2003-2007): 700 MHz
600 MHz / 100 MHz/ 55 mm RT bore
100 HTS (Bi-2223 @4.2 K)
40 Double Pancake Coils
55-mm RT bore
600 LTS (Nb-Ti/Nb3Sn @4.2 K)
140-mm COLD bore
Bi-2223-Tape
Double Pancake Coil
126.5
78.2
401.6
[JASTEC]
* A US HTS activity (supported by NIH)
Y. IWASA (FBML)
[email protected]
DAPNIA Day  HTS
Saclay (03/07/2006)
18
3-Phase MIT 1-GHz LTS/HTS NMR Magnet Project (cont.)
Nb-Ti
Nb3Sn
Phase 3 (2008-20011)*: 1 GHz
760 MHz / 240 MHz / 63 mm RT bore
760 LTS (Nb-Ti/Nb3Sn @4.2 K)
175-mm COLD bore
Bi-2223
240 HTS (Bi-2223 @4.2 K)
63-mm RT bore
64 Double-Pancake Coils
87
175
* NIH yet to approve Phase 3
Y. IWASA (FBML)
[email protected]
DAPNIA Day  HTS
Saclay (03/07/2006)
[JASTEC (2005)]
19
Grenoble/Saclay
1.2-GHz LTS/HTS NMR Magnet Project
Phase 1: 850 Cu/350 HTS
850 (20 T)/20 MW Cu Magnet (Grenoble)
3-Coil HTS (Bi-2212) Insert
(Saclay)
136
[Jean-Michel Rey (2006)]
Y. IWASA (FBML)
[email protected]
160
DAPNIA Day  HTS
Saclay (03/07/2006)
20
28
Bo [T]
1.2
Grenoble/
Saclay?
March Towards 1 GHz & 1.2 GHz
26
24
1000
22
20
: SUPERCONDUCTING—LTS/HTS [GHz]
18
: SUPERCONDUCTING—LTS [MHz]
900
1
950
930
MIT?
800
750
: NON-SUPERCONDUCTING [MHz]
16
14
600
12
MIT
MIT
500
10
360
8
270
6
220
200
4
2
0
40
60 100
YEAR
30
50
54 58 62
Y. IWASA (FBML)
[email protected]
66 70 74
78
82
86 90 94 98
DAPNIA Day  HTS
Saclay (03/07/2006)
02 06
08
10 12
14
21
[Based on Kobe Steel data (1998)]
Challenges
Conductor
• Develop “long” (~10 km) conductors
• Reduce AC losses in Bi-2223 & YBCO (tapes)
• Reduce price/performance ($/kA m)
For NMR/MRI magnets
• Develop superconducting joints
Y. IWASA (FBML)
[email protected]
DAPNIA Day  HTS
Saclay (03/07/2006)
22
Current-Carrying Capacity vs. Price/Length Plots
105
$1/kA m
I [A]
104
$10/kA m
ITER
 Nb3Sn
(5.5 K; 13 T)
$100/kA m
Nb-Ti 
MgB2 (4.2K; 6T)
$2-5/kA m
(2008-2010)
(20 K; 2 T.)
$200/kA m
103
Nb3Sn
Tape
(10 K; 1 T)
YBCO (2008-2010)
(77.3 K; s.f.)
(2006)
 Bi-2223
(77.3 K; s.f.)
100
10
0.1
1
10
100
Price [$/m]
Y. IWASA (FBML)
[email protected]
DAPNIA Day  HTS
Saclay (03/07/2006)
1,000
10,000
23
Challenges (continuation)
Cryogenics
• Easier for HTS than for LTS, but its ratio of compressor power
QRT to refrigeration power at Top, Qop , needs MUCH (QRT /Qop )
QRT /Qop vs. Top for Selected Qop
10000
1W
10 W
100 W
1 kW
100 kW
QRT /Qop
1000
100
10
CARNOT
1
0
10
20
30
40
50
60
70
80
Top [K]
Y. IWASA (FBML)
[email protected]
DAPNIA Day  HTS
Saclay (03/07/2006)
24
Comparison of HTS vs. Cu Devices
For an HTS device to compete its Cu counterpart operating at
room temperature (RT), its dissipation at Top, PHTS [W/m],
multiplied by the refrigerator’s compressor-to-cooling power
ratio, QRT /Qop, < Cu’s Joule dissipation, PCu [W/m]
PHTS  (QRT /Qop) < PCu
PCu /PHTS > QRT /Qop
1W
Qop
Challenge: Cryogenics
• QRT /Qop  , i.e., refrigerator
efficiency
1 kW
10 kW
QRT /Qop
Top [K]
4.2
10
20
30
50
77
100 W
8000
1650
600
350
120
55
1500
500
220
110
50
22
850
380
140
70
30
15
400
180
75
45
20
10
Challenge: AC Losses
• PHTS  to satisfy PCu /PHTS > QRT /Qop
Y. IWASA (FBML)
[email protected]
DAPNIA Day  HTS
Saclay (03/07/2006)
25
Comparison of Two Systems: An Illustrative Example
• HTS (YBCO) & Cu Transmission “Lines”  Based on HTS
Refrigeration Power Requirement, Qop  PHTS vs. PCu = I2R
HTS
w
Cu
Dimensions & Characteristics
of “Basic (Ic =100 A) HTS tape
YBCO
Substrate;
stabilizer,
etc.
w = 4x103 m (4 mm)
s =
m (1 µm)
 = 100
s = 1x104 m (100 µm)
s
s
Y. IWASA (FBML)
[email protected]
1x106
Cu
w
Ic = 100 A (77.3 K, s.f.)
Jc = Ic / (ws)= 2.5x1010 A/m2
DAPNIA Day  HTS
Saclay (03/07/2006)
s
26
Two-System Comparison (continuation)
Self-Field AC Loss Power/length, PHTS [W/m], of HTS Line
composed of n 100-A “basic” tapes operated at IT = n  (It /Ic)
PHTS
Power Density/length, Pcu [W/m], in Cu Tape
Cu
w
Pcu
Figure-Of-Merit (FOM):
Y. IWASA (FBML)
[email protected]
Pcu
PHTS
DAPNIA Day  HTS
Saclay (03/07/2006)
QRT
Qop
s
27
Pcu /PHTS & FOM vs. i for 10-kA (nominal) Lines @77 K
10000
33 W/km (PCu/PHTS=6460) 100 W @77 K (QRT / Qop =22) FOM=294
540 W/km (1600) 1 kW @77 K (QRT / Qop =15); 107
1000
Pcu / PHTS
2.8 kW/km (700)
9.1 kW/km (380) 10 kW @77 K (10); 38
10 kW @77 K (10); 70
HTS non-competitive to Cu
100
77-K operation possible, but, at least in
this example, a 10-kA HTS line superior
to the Cu line only when the HTS line
operated at currents below 5 kA
10
1
0
Y. IWASA (FBML)
[email protected]
0.2
0.4
i
0.6
DAPNIA Day  HTS
Saclay (03/07/2006)
0.8
1
28
Two-System Comparison (continuation)
=
Pcu
PHTS
QRT
Qop
Ways to improve FOM:
• Improved YBCO (Jc @77 K )
• Thinner substrate ( )
Challenges: YBCO
• Improved refrigerator (QRT / Qop) Challenge: Cryogenics
LTS’s Failure in Power Applications:
• QRT /Qop @ 4.2 K too large to satisfy PCu /PLTS > [QRT /Qop]4.2 K
Y. IWASA (FBML)
[email protected]
DAPNIA Day  HTS
Saclay (03/07/2006)
29
Protection
“Expensive” magnets must be protected from permanent damages
• LTS magnets generally rely on NZP
(normal zone propagation) to spread out
the resistive zone to keep the “hot spot”
temperature well below 300 K
• In HTS magnets, NZP velocities (longitudinal
& transverse), compared with those in LTS
magnets, very slow, leading to a dangerously
high “hot spot” temperature
Jm
 m (T )km (T )
U (T ) 
Ccd (T ) (Tcs  Top )
for HTS Ccd (T) very large UHTS << ULTS
Y. IWASA (FBML)
[email protected]
DAPNIA Day  HTS
Saclay (03/07/2006)
NZP
Quench
Initiation
Zone
(“Hot spot”)
30
Challenges (continuation)
Protection
• Develop fail-safe protection techniques
• Develop normal-zone detection techniques
Y. IWASA (FBML)
[email protected]
DAPNIA Day  HTS
Saclay (03/07/2006)
31
Important Activities for HTS
• BUILD and operate MAGNETS: LTS, LTS/HTS, HTS
• Enhance test facilities for evaluation of HTS
 Ic measurement (up to: 500 A; 30 T; 100 K; 0.5%)
• R&D Areas, besides conductor
 Protection
 Cryogenics  QRT /Qop or efficiency even at 77 K
 Make cryogenics LESS visible to the user 
o solid-cryogen may help achieve this goal
 Superconducting joints (for NMR/MRI)
Y. IWASA (FBML)
[email protected]
DAPNIA Day  HTS
Saclay (03/07/2006)
32
Market Penetration for HTS
• HTS applications most likely to succeed and benefit
society, i.e., market penetration, include:
DC or nearly DC devices: those already conquered by LTS,
e.g., NMR/MRI; HEP; even fusion
 If HTS replacing technology to LTS  its marketplace
penetration to be decided by ECONOMICS
 Conductor cost/performance ($/ka m); AC losses;
Cryogenic efficiency
 If HTS enabling technology, e.g., high-field NMR and MRI,
its success dictated by HTS PERFORMANCE
Y. IWASA (FBML)
[email protected]
DAPNIA Day  HTS
Saclay (03/07/2006)
33
Conclusions
• HTS for NMR/MRI: work already started
• HTS for HEP & fusion: NOT TOO EARLY to begin planning
• For the most prized application  in terms of sheer volume 
electric power, LTS NOT ENABLING: hope hinges on HTS
• HTS  opportunities & challenges  will keep ALL of us
innovative, relevant, and productive for a long time !
Merci beaucoup
Y. IWASA (FBML)
[email protected]
DAPNIA Day  HTS
Saclay (03/07/2006)
34